As far as I can see only CMS tasks failed on your computers.
The error log tells you what happened:
"207 (0x000000CF) EXIT_NO_SUB_TASKS"

This means that the project wasn't able to deliver a workpackage to run inside a fresh VM and is mostly caused by a WMAgent outage.
You may check the CMS MB to see if other users report the same problem or if the project team (Ivan) suggests to stop pulling CMS tasks for a while.

As far as I can see only CMS tasks failed on your computers.
The error log tells you what happened:
"207 (0x000000CF) EXIT_NO_SUB_TASKS"

This means that the project wasn't able to deliver a workpackage to run inside a fresh VM and is mostly caused by a WMAgent outage.
You may check the CMS MB to see if other users report the same problem or if the project team (Ivan) suggests to stop pulling CMS tasks for a while.

OK - so I waited almost 2 months now and tried a couple of CMS WUs- and now I get, after over 2 hours elapsed time the following status message:

Postponed: VM job unmanageable, restarting later

At the same time LHCB, sixtrack and theory are running nicely.
Furthermore, there are no more WU being downloaded -

There is enough Ram (64 GB), there is enough free disk space (>400GB) and it is full moon outside ...
So much respective unattended running of the LHC project.

As far as I understand using VBOX takes all the problems ouf crunching since one doesn't have to adapt the progs to the crunchers rig ???
Great idea.

I am getting the "postponed: VM job unmanegable ..." message on three of my rigs.
Since BOINC does not download WUs till the postponed WU is automatically restarted, I have stopped executing all VBOX projects (theory, cms, lhcbs) till this problem gets fixed.

I made this decision because I am also now getting the following message:

"Postponed: Waiting to acquire slot directory lock. Another instance may be running"

As I am running my rigs more or less unattended, I missout on crunching time, because of the matter that new WU are not downloaded when other
ones (six track) have finished.

When I have time I will update VBox from 5.2.6 to 5.2.8 - maybe the problem has been fixed.

"Postponed: Waiting to acquire slot directory lock. Another instance may be running"

I had the same problem a few weeks ago. So I opened the Oracle Virtual Box Manager and noticed that some VM jobs had hung up themselves. They showed up in the VB Manager in addition ot the ones that were listed in the BOINC Manager.
So what I did was: I deleted these "dead" jobs, and that was it. Everything worked fine again (I don't remember though whether I closed down BOINC and restarted it - mayby this must be done).

Well, in my case here the number of jobs (WUs) shown in VBOX is the same as in BOINC.
Some are powered off - some are saved - depending

Waiting a day or so (or restarting BOINC) seems to solve the problem/s.
The bad part is, that during the waiting period of one day (if unattended), BOINC will not download and start any other LHC WU (i.e. six track which
is non VBOX)!

The WUs finish OK and without error.

Also, I do not like the idea of having to "monitor" the LHC WUs - maybe I'm a bit picky, but it is not my job to solve these things.

I'm wondering why, that no other crunchers are having the same "troubles" -- I'm not doing anything exotic.